feat(2024): add day 5 part 1

go/2024/puzzles/day05/main.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"fmt"
+	"slices"
+	"strings"
+
+	"github.com/believer/aoc-2024/utils"
+	"github.com/believer/aoc-2024/utils/files"
+)
+
+// There are things that can be improved. I think we can use
+// the slices.SortFunc in some way for part 2 as well, but no
+// time now.
+func main() {
+	fmt.Println("Part 1: ", part1("input.txt"))
+	fmt.Println("Part 2: ", part2("input.txt"))
+}
+
+func part1(name string) int {
+	parts := files.ReadParagraphs(name)
+	total := 0
+	orderingRules := map[string][]string{}
+	updates := parts[1]
+
+	for _, r := range parts[0] {
+		parts := strings.Split(r, "|")
+
+		orderingRules[parts[0]] = append(orderingRules[parts[0]], parts[1])
+	}
+
+	for _, u := range updates {
+		isValid := true
+		pages := strings.Split(u, ",")
+
+		for i, p := range pages {
+			if i+1 > len(pages) {
+				continue
+			}
+
+			before := pages[:i]
+			rules := orderingRules[p]
+
+			for _, r := range rules {
+				if slices.Contains(before, r) {
+					isValid = false
+				}
+			}
+		}
+
+		if isValid {
+			middle := pages[len(pages)/2]
+
+			total += utils.MustIntFromString(middle)
+		}
+	}
+
+	return total
+}

go/2024/puzzles/day05/main_test.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPart1(t *testing.T) {
+	t.Run("Part 1", func(t *testing.T) {
+		expected := 143
+		actual := part1("test-input.txt")
+		assert.Equal(t, expected, actual)
+	})
+}
+
+func TestPart2(t *testing.T) {
+	t.Run("Part 2", func(t *testing.T) {
+		expected := 123
+		actual := part2("test-input.txt")
+		assert.Equal(t, expected, actual)
+	})
+}
+
+func BenchmarkPart1(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		part1("input.txt")
+	}
+}
+
+func BenchmarkPart2(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		part2("input.txt")
+	}
+}

go/2024/puzzles/day05/test-input.txt

@@ -0,0 +1,28 @@
+47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47